1. Field of the Invention
The invention relates to an intake regulating system of engine, and more particularly, to an intake regulating system of engine that makes the engine's discharged gas pass through an air regulating valve and mix with the outside air, then reintroduce the mixed air back into the engine for re-combustion.
2. Description of the Prior Art
A crankcase forced ventilating system generally called PCV (Positive Crankcase Ventilation) is normally provided on the top of the cap of the rocker arm of an automobile engine. The PCV device is generally provided between the “ventilation hole” of the crankcase and the intake manifold.
When the engine is working, there are toxic gases that contain hydrocarbon (HC) and carbon monoxide (CO) etc. leaking from the combustion chamber to the crankcase, and discharging to the atmosphere causing air pollution. The purpose of providing the PCV device is to reintroduce the discharged and leaked gases back to the combustion chamber for re-combustion instead of discharging all of them into the atmosphere. The automobiles manufactured by all the countries are stipulated to equip with PCV device for compelling the toxic gases that is harmful to the health to be recycled, thereby, preventing hydrocarbon (HC) and carbon monoxide (CO) etc. from discharging into the atmosphere directly causing air pollution.
In general, the common limit for the ON/OFF action time of the intake valve, regardless of single or multiple intake valves of engine, of the conventional carburetor is only around 1/100 second when the engine velocity reaches 3,000 rpm (revolution per minute) wherein the valve's ON time contains 30% while the valve's OFF time contains 60%. Therefore, it becomes an important issue for people skilled in the art to pursue how to supply effective and sufficient air in the instant of air intake of the intake valve.
FIG. 1 is a schematic diagram of an intake regulating system of engine of the prior art while FIG. 2 is a cross-sectional view of an air regulating valve of the intake regulating system of engine of the prior art. In the light of the above-mentioned problems and as shown in FIG. 1 and FIG. 2, there is an intake regulating-device of engine (1) on the market. The intake regulating-device of engine of the prior art is connected to the air tube of the engine to form an intake regulating system of the engine.
The intake regulating-device of engine includes a housing (11), a pair of springs (12) and (13), a valve piston (14), and a valve regulating knob (15). An inlet hole (110), an outlet hole (111), and a slender hole (112) connecting to the negative pressure are also furnished in the housing (11). The valve piston (14) is contained within the housing (11) and is capable of reciprocally sliding therein and forming a valve.
An end of the valve piston (14) is an air-tight slider (141) having a couple of compression rings (142) and (143) that make the air-tight slider (141) maintain air-tight while perform sliding with the interior surface of the housing (11). The other end of the valve piston (14) provides a conic surface (144) capable of air-tight contacting to the housing (11).
For the sake of maintaining air-tight contact between the conic surface (144) of the valve piston (14) and the housing (11) to intercept the air flow between the inlet hole (110) and the outlet hole (111), the resilient force of the spring (13) has to be greater than that of the spring (12).
As shown again in FIG. 1, when the engine (2) starts working, the intake valve has opened during the intake stroke, and the piston is moving downward, drawing air from an air cleaner (21) through an air pipe (210), a throttle (22), an intake manifold (23), and the air inlet (20). A mixture of air and gasoline vapor is then drawn into the cylinder. Conventional carburetor makes use of a Venturi tube to take in the combustion fuel automatically. However, the new fuel injection engine employs ECU (Electronic Control Unit) (220) to control the fuel nozzle making the fuel-air mixture maintain a constant fuel-air ratio in accordance with the detecting result of the AFM (Air Flow Meter) to draw the air-fuel mixture into the combustion chamber via the air inlet (20) for generating power.
For keeping the pressure balance between the crankcase (28) and the outside atmosphere, a hole connected to a breather hose (24) and the air pipe (210) for communicating with the outside air is provided above the liquid surface of oil in the crankcase 28 of the engine (2). What is more, part of the gas in the crankcase 28 can discharge through the breather hose (24) via the air pipe (210) and enter the intake manifold (23) together with the air drawing from the atmosphere. The other part of the gas passes through the PCV (Positive Crankcase Ventilation) device (25), intake manifold (23) and enters the air inlet (20) of the engine (2).
As shown in FIG. 1, the intake regulating-device of engine (1) of the prior art is communicating with the intake manifold (23) of the engine (2). As the car driver steps' on the accelerator for accelerating, the cylinder of the engine (2) will draw more air from the atmosphere causing the pressure drop at the outlet hole (111). Consequently, both ends of the air-tight slider (141) positioned on top of the valve piston (14) create pressure difference.
When the pressure difference is created and becomes larger than the unbalanced resilient force between the springs 12 and 13, the conic surface (144) of the valve piston (14) moves downward. The air path between the inlet hole (110) and the outlet hole (111) is varied according to the moving of the conic surface (144) of the valve piston (14).
As the conic surface (144) moves downward, the outside air can be drawn into the inlet hole (110), and therefore passing through the outlet hole (111), intake manifold (23) and air inlet (20) of engine, to provide sufficient and effective air for combustion. Preferably, the inlet hole (110) is connected with an air cleaner (1101) to prevent dirty air from getting in and for protecting the intake regulating-device of engine (1) and the engine (2).
In actual operation, it is found that the engine (2) of the prior art shown in FIG. 1 has the following demerits:
1. The oil vapor leaking from the combustion chamber of the engine to the crankcase 28 and entering directly from the breather hose (24) to the air pipe (210) and the intake manifold (23) may condense on the wall of the pipe if it comes across cold air causing greasy dirt deposit that is hard to clean up.
2. The intake regulating-device of engine (1) of the prior art is unable to effectively regulate the limiting position that is capable to open the valve piston (14) to adapt to the requirements of different specification for the engines.